Field of the Invention
This invention relates to a portable, user-controlled motorized walker that delivers haptic walking-speed cues specific to the environment by virtue of its motion, to aid the gait of those at risk for falling in the clinic and in the real world.
Description of Related Art
Aging, injury and disease can lead to patients experiencing a loss of stability and being at a greater risk for falls. Fall-related injuries contribute to reduced activity, reduced quality of life, depression, social isolation and mortality in vulnerable populations. Fall incidents are the third leading cause of chronic disablement in older persons and account for more than 80% of the hospitalizations for injuries in older adults. In 2007, approximately 250,000 hip fractures from falling occurred in the U.S. This figure is expected to double in the next 30 years with the growth of the group at greatest risk, those older than 65.
Of persons aged 65 years and older, 30% have fallen at least once, and 15% have fallen at least twice. Ten percent of falls lead to bone fractures and other serious injuries. Among the residents of long-term care facilities, 45-70% fall each year, with 50% experiencing multiple falls. Injuries caused by falling include hip fractures, other leg injuries, and internal organ damage including traumatic brain injuries. About one quarter of the people who experience a fall consult a hospital emergency room or primary care physician after the incident. Approximately 20-30% of those who fall suffer injuries that increase dependence, and 25% of hip fracture patients die within a year of injury.
Based on 1997 data, the total health care cost of falls among community-dwelling adults was approximately $7.8 billion (adjusted for inflation to 2002). In 2004, the average hospitalization cost for a fall injury was $17,500. A study of military veterans showed the average annual individual hip fracture Medicare payment was $69,389 in 2007. The total direct cost of fall injuries for people 65 and older in 2000 reached $19 billion. The 2005 annual cost of treating fractures from falling was $12 billion. Another estimate yielded an annual direct cost of $20.8 billion from falls among the elderly, the sick, and among people in the workplace. The Center for Disease Control and Prevention adjusts this to $54.9 billion annually by 2020 including direct and indirect costs, inflation and population projections.
While a cane can provide a user with greater stability, more than 1.5 million people in the United States use standard or wheeled walkers, which provide even greater stability and assistance than a cane.
Aging and Parkinson's disease are two causes that lead to patients using walkers, with changes in somatosensory and musculoskeletal systems resulting in a drop in the sensory information that guides normal postural control, leading to falls. Parkinson's disease is the most commonly reported diagnosis in people over 65, and is the most common neurological disorder associated with gait disturbance and falling. Freezing of gait, the most disruptive effect of Parkinson's disease on gait, can lead to falls, loss of mobility and independence. During freezing of gait, individuals move forward with very small steps or experience leg trembling in place despite efforts to walk regularly. Of falls suffered by individuals with Parkinson's disease, 70-80% are related to individual factors such as poor postural control or freezing, as opposed to environmental factors. However, freezing of gait tends to occur under specific contexts such as transiting narrow passages, turning or crossing the street.
Recent studies find that 50-68% of people with Parkinson's disease experience falls. Half of this group are likely to fall again—a likelihood nine times that of healthy individuals. Parkinson's disease also multiplies the risk of hip fracture by nine. The cost of caring for an individual with Parkinson's disease is doubled by a broken bone and tripled by a broken hip. For individuals with Parkinson's disease, 45% have a fear of falling and 44% restrict activity, which can lead to weakness which can lead to more falling and greater costs to all. Falling and resulting dependence is also associated with negative changes in quality of life, depression, reduction of activity and social isolation. Falling also creates more stress for caregivers, which can lead to institutionalization.
Interventions intended to improve posture and gait may involve visual or auditory sensory cues, provided via either a mechanism or personal coaching. However, most such interventions do not carry over from the clinic to everyday living, and performance returns to pre-intervention levels. Haptic cuing (from touch) devices overcomes the shortcomings of retention of interventions, particularly in the realm of gait initiation and freezing of gait in individuals with Parkinson's disease, because they engage postural reflexes to stabilize posture and require no learning.
Postural instability associated with Parkinson's disease is not helped by dopaminergic therapy. Therefore, a great need exists for providing patients with Parkinson's disease with support to prevent falls, which will reduce health care costs, increase life expectancy, and provide improved mobility, independence and quality of life. As noted above, walkers can provide additional stability for users. However, walkers slow the user down and require additional effort to push.
It is therefore an object of the present invention to provide a comprehensive solution to provide a motorized walker that can enable users to walk without being slowed by the walker and without needing to exert themselves to push the walker forward.
Another object is to provide additional haptic speed cues to inform the user's posture and locomotion control to prevent falling. The walker may reduce the risk of falling directly by (1) increasing haptic feedback to the user and (2) avoiding immediate conditions that lead to falling by its sensor-feedback-driven automatic guidance systems, and also (3) indirectly by providing walking exercise that increases user strength and fitness.